Rock Identifier
Malachite (Copper(II) carbonate hydroxide [Cu2CO3(OH)2]) — mineral
mineral

Malachite

Copper(II) carbonate hydroxide [Cu2CO3(OH)2]

Hardness: 3.5–4.0 Mohs; Color: Bright green, dark green, or blackish-green; Luster: Adamantine to vitreous or silky; Crystal System: Monoclinic; Cleavage: Perfect in one direction, but rarely seen in massive forms.

Hardness
3
Color
Bright green, dark green, or blackish-green
Luster
Adamantine to vitreous or silky
Identified More mineral
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Physical properties

Hardness: 3.5–4.0 Mohs; Color: Bright green, dark green, or blackish-green; Luster: Adamantine to vitreous or silky; Crystal System: Monoclinic; Cleavage: Perfect in one direction, but rarely seen in massive forms.

Formation & geological history

Forms in the oxidized zones of copper deposits where carbonated waters interact with copper-bearing minerals. Typically found in hydrothermal veins and sedimentary rocks resulting from the weathering of copper ores.

Uses & applications

Used primarily as an ornamental stone, in jewelry (cabochons and beads), and historically as a green pigment in paints. It is also an ore of copper.

Geological facts

Malachite was used as a mineral pigment in green paints from antiquity until about 1800. It is often found associated with azurite, where the two minerals may form intergrowths known as 'azurmalachite'.

Field identification & locations

Identified by its vivid green color and typical botryoidal (grape-like) or banded growth patterns. In the field, look for green staining on rocks near copper mines or outcrops. It will effervesce (fizz) in contact with dilute hydrochloric acid.